TWI749487B - A method and a device for controlling safe lifting of silicon melt crucible - Google Patents

Abstract

The present invention provides a method and a device for controlling safe lifting of silicon melt crucible. The method comprises steps of: obtaining an initial position height of the crucible POS₀ , an initial liquid level of a silicon melt in the crucible D₀ , and an initial distance between an liquid level of the silicon melt in the crucible and a draft tube MG₀ ; obtaining a current position height POS_L of the crucible and the current liquid level D_L of the silicon melt in the crucible when a length of a currently grown silicon ingot is L; and determining whether a current position of the crucible is safe when the length of the currently grown silicon ingot is L according to the initial position height POS₀ , the current position height POS_L , the initial liquid level D₀ , and the current liquid level D_L .

Description

Method and device for controlling safe lifting and lowering of silicon melt crucible

The invention relates to the field of semiconductor manufacturing, in particular to a method and device for controlling the safe lifting and lowering of a silicon melt crucible.

The Czochralski method (Cz) is an important method for preparing silicon single crystals for semiconductors and solar energy. It uses a thermal field composed of carbon materials to heat the high-purity silicon material put into the crucible to melt it, and then use the seed crystal to immerse it into the melt. After a series of (seeding, shoulder setting, equal diameter, finishing, cooling) processes in the body, a single crystal rod is finally obtained.

Referring to FIG. 1, it shows a schematic diagram of a semiconductor crystal growth apparatus. The semiconductor crystal growth device includes a furnace body 1 in which a crucible 11 is provided, a heater 12 for heating the crucible 11 is provided outside the crucible 11, and a silicon melt 13 is contained in the crucible 11.

A pulling device 14 is provided on the top of the furnace body 1. Under the driving of the pulling device 14, the seed crystal pulls the silicon crystal rod 10 from the liquid surface of the silicon melt, and at the same time, a heat shield device is arranged around the silicon crystal rod 10. Exemplarily, as shown in FIG. 1, the heat shield device includes a diversion cylinder 16, which is set in a conical barrel shape, which serves as a heat shield device to isolate the quartz crucible and the crucible during the crystal growth process. The heat radiation generated by the silicon melt on the surface of the crystal increases the cooling rate and axial temperature gradient of the crystal rod, and increases the number of crystal growth. On the other hand, it affects the thermal field distribution on the surface of the silicon melt, and avoids the center and the center of the crystal rod. The axial temperature gradient difference at the edge is too large to ensure the stable growth between the crystal rod and the liquid surface of the silicon melt; at the same time, the guide tube is also used to divert the inert gas introduced from the upper part of the crystal growth furnace to make it larger The velocity of flow through the surface of the silicon melt achieves the effect of controlling the oxygen content and impurity content in the crystal.

In order to realize the stable growth of silicon crystal rods, a driving device 15 that drives the crucible 11 to rotate and move up and down is also provided at the bottom of the furnace body 1. The driving device 15 drives the crucible 11 to keep rotating during the crystal pulling process to reduce the heat of the silicon melt. The asymmetry makes the silicon crystal column grow in equal diameter. The driving device 15 drives the crucible 11 to move up and down to ensure that the silicon melt has a stable liquid surface position and the stability of the crystal rod growth.

However, when the driving device 15 drives the crucible 11 to move up and down, it often happens that the position of the crucible exceeds or falls below the predetermined position, which causes the liquid level of the silicon melt to be higher or lower, which affects the quality of crystal growth; moreover, in the crucible After moving upward to a certain extent beyond the liquid level of the silicon melt, it comes into contact with the deflector tube 16, causing the device to be damaged.

For this reason, it is necessary to propose a new method and device for controlling the safe lifting and lowering of the silicon melt crucible to solve the problems in the prior art.

A series of simplified concepts are introduced in the content of the invention, which will be explained in further detail in the detailed implementation section. The inventive content part of the present invention does not mean an attempt to limit the key features and necessary technical features of the claimed technical solution, nor does it mean an attempt to determine the protection scope of the claimed technical solution.

The present invention provides a method for controlling the safe lifting and lowering of a silicon melt crucible, the method comprising: obtaining the initial position height POS ₀ of the crucible, the initial liquid level D ₀ of the silicon melt in the crucible, and the crucible _{The initial distance MG 0} between the liquid level of the silicon melt and the guide tube _{; to obtain the current position height POS L} of the crucible when the length of the currently grown silicon crystal rod is L and the current liquid level of the silicon melt in the crucible Height D _L ; According to the initial position height POS ₀ , the current position height POS _L , the initial liquid level D ₀ and the current liquid level D _L, it is determined when the length of the currently grown silicon crystal rod is L Describe whether the current position of the crucible is safe.

Exemplarily, judge whether the current height of the crucible is safe when the length of the currently grown silicon crystal rod is L: When α ₀ POS _L -α ₁ POS ₀ <β ₀ D ₀ -β ₁ D _L +β when ₂ MG ₀ + L _S, the current position of the crucible is highly safe; when _{α 0 POS L -α 1 POS 0} > β 0 D 0 -β 1 D L + β 2 MG 0 + L S, the crucible The current position of is not safe, and the L _S is the set safety control height margin.

Illustratively, further comprising a height position according to the initial POS _0, the current location of the initial height of the POS level height _L D ₀ and the current height of the liquid level D _L Analyzing current grown silicon rod length is L Whether the liquid level position of the silicon melt in the crucible is stable.

Exemplarily, it is judged whether the position of the silicon melt liquid level in the crucible is stable when the length of the currently grown silicon crystal rod is L according to the following rules: When α ₀ POS _L -α ₁ POS ₀ ＜β ₀ D ₀ -β ₁ When D _L +β ₂ MG ₀ +L _U and α ₀ POS _L -α ₁ POS ₀ > β ₀ D ₀ -β ₁ D _L + β ₂ MG ₀ -L _L , the silicon melt liquid in the crucible The surface position is stable; when α ₀ POS _L -α ₁ POS ₀ ＞β ₀ D ₀ -β ₁ D _L +β ₂ MG ₀ +L _U or α ₀ POS _L -α ₁ POS ₀ ＜β ₀ D ₀ -β ₁ D _L + β ₂ MG ₀ -L _L , the liquid level position of the silicon melt in the crucible is unstable; among them, α ₀ , α ₁ , β ₀ , β ₁ and β ₂ are coefficient factors, and L _U and L _L is the control margin of the upper limit of the set liquid level and the lower limit of the set liquid level respectively.

Silicon rod when acquiring initial mass of silicon melt in the crucible and the current generated by G ₀ of length L: Exemplarily, the step of obtaining the liquid level height _L of the current D in the crucible silicon melt level comprises Quality G _L ; obtain the volume V _{r of the} remaining silicon melt of the crucible according to the _{initial mass G 0} of the silicon melt in the crucible _{and the mass G L of} the currently generated silicon ingot; The volume V _{r of the} remaining silicon melt and the diameter of the crucible are calculated to obtain the current height D _{L of the} liquid level of the silicon melt in the crucible.

，

為所述矽晶棒的橫截面積，

為所述矽晶體的密度。 _{Exemplarily, the obtaining of the mass G L} of the silicon ingot when the current generation length is L is obtained by calculation using the following formula:

,

Is the cross-sectional area of the silicon crystal rod,

Is the density of the silicon crystal.

Exemplarily, the acquisition of the quality G _L of the currently generated silicon ingot is obtained by directly measuring the quality of the currently generated silicon ingot.

The present invention also provides a method for controlling the safe lifting and lowering of a silicon melt crucible, including: obtaining the current position height POS _L of the crucible when the length of the currently grown silicon crystal rod is L; and obtaining the growth length of N silicon crystal rods _{The position height POS Li} of the crucible at L, where i=1, 2...N; Obtain the position median POSM _L and the position standard deviation DEV _{L of the position POS Li} of the crucible; According to the position height POS _L , the position median POSM _L and the position standard deviation DEV _L determine whether the current height of the crucible is safe when the length of the currently grown silicon crystal rod is L.

Exemplarily, judge whether the current height of the crucible is safe when the length of the currently grown silicon crystal rod is L: When γ ₀ POS _L -γ ₁ POSM _L <DEVL×y _S , the current position of the crucible is The position is highly safe; when γ ₀ POS _L -γ ₁ POSM _L > DEVL×y _S , the current position of the crucible is unsafe; among them, γ ₀ and γ ₁ are coefficient factors, and y _S is a set safety control factor.

Exemplarily, it further includes the silicon melt liquid in the crucible when the length of the currently grown silicon crystal rod is judged to be _L according to the position height POS L, the position median POSM _L and the position standard deviation DEV _L Whether the surface position is stable.

Exemplarily, it is determined whether the position of the silicon melt liquid level in the crucible is stable when the length of the currently grown silicon crystal rod is L according to the following rules: γ ₀ POS _L -γ ₁ POSM _L ＜DEV _L ×y _U and When POS _L -POSM _L > DEV _L ×y _L , the liquid level position of the silicon melt in the crucible is stable, γ ₀ POS _L -γ ₁ POSM _L > DEV _L ×y _U or POS _L -POSM _L < When DEV _L × y _L , the position of the silicon melt liquid level in the crucible is unstable; among them, γ ₀ and γ ₁ are coefficient factors, and y _U and y _L are the highest factor of the set liquid level and the set liquid level, respectively The lowest factor.

_{Exemplarily, the method for obtaining the position POS i} of the crucible when the growth length of N silicon crystal rods is L includes: obtaining the position height POSiM of the crucible when each silicon crystal rod is grown for each length M; _{Obtain the position POS Li} of the crucible when the growth length L of each silicon _ingot is obtained from the plurality of position heights POS iM of a silicon ingot.

Exemplarily, the method for obtaining the position median POSM _L and the position standard deviation DEV _{L of the position POS i of the crucible includes: obtaining the position median POSM M of} the crucible for each growth length M according to the POS _iM And the position standard deviation DEV _{L , and draw them into a table or curve respectively; obtain the position median POSM L} and position standard deviation DEV _{L of} the crucible when the growth length of the crystal rod is L from the table or curve.

Exemplarily, when it is determined that the position of the crucible is outside the safe range, the crucible is locked at the current position without moving up and down.

Exemplarily, when it is determined that the position of the liquid level in the crucible is unstable, an alarm is issued.

The invention also provides a device for controlling the safe lifting and lowering of the silicon melt crucible, which includes: A memory and a processor storing executable computer program instructions, and when the processor executes the executable computer program instructions, the method described in any one of the above is executed.

Exemplarily, it further includes a locking device. When the processor determines that the position of the crucible is outside the safe range, the locking device locks the crucible at the current position without moving up and down.

Exemplarily, it further includes an alarm device. When the processor determines that the position of the liquid level in the crucible is unstable, the alarm device issues an alarm.

According to the method and device for controlling the safe lifting and lowering of a silicon melt crucible, the position of the crucible and the position of the liquid level in the crucible are used to determine whether the current position of the crucible during the crystal pulling process is within a safe range, so as to avoid the crucible being caused by the crucible during the crystal pulling process. The up and down movement of the crucible exceeds the limit and damage occurs. At the same time, the stability of the silicon melt liquid level in the crucible is ensured during the up and down movement of the crucible, which further ensures the stable growth of the silicon crystal rod.

In the following description, a lot of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features known in the art are not described.

In order to thoroughly understand the present invention, a detailed description will be provided in the following description to illustrate the method of the present invention. Obviously, the implementation of the present invention is not limited to the specific details familiar to those skilled in the semiconductor field. The preferred embodiments of the present invention are described in detail as follows. However, in addition to these detailed descriptions, the present invention may also have other embodiments.

It should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly dictates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and/or "including" are used in this specification, they indicate the presence of the described features, wholes, steps, operations, elements, and/or components, but do not exclude the presence or One or more other features, wholes, steps, operations, elements, components, and/or combinations thereof are added.

Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms, and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the concept of these exemplary embodiments to those of ordinary skill in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity, and the same reference numerals are used to denote the same elements, and thus their descriptions will be omitted. Example one

In order to solve the technical problems in the prior art, the present invention provides a method for controlling the safe lifting and lowering of a silicon melt crucible. The method includes: obtaining the initial position height POS ₀ of the crucible, and the initial liquid of the silicon melt in the crucible The surface height D _{0 and the initial distance MG 0} between the silicon melt level in the crucible and the deflector tube _{; obtain the current position height POS L} of the crucible when the length of the currently grown silicon crystal rod is L and the _{The current liquid level D L} of the silicon melt in the crucible; judge the current growth according to the initial position height POS ₀ , the current position height POS _L , the initial liquid level D ₀ and the current liquid level D _L Whether the current position of the crucible is safe when the length of the silicon crystal rod is L.

The following is an exemplary description of a method for controlling the safe lifting and lowering of a silicon melt crucible proposed by the present invention with reference to Figs. 1 and 2. Fig. 1 is a schematic diagram of a semiconductor crystal growth device according to the structure; Fig. 2 is an embodiment according to the present invention A flow chart of a method for controlling the safe lifting and lowering of a silicon melt crucible. First, referring to Figure 2, step S201 is performed: obtaining the initial position height POS ₀ of the crucible, the initial liquid level D ₀ of the silicon melt in the crucible, and the difference between the silicon melt liquid level in the crucible and the deflector tube The initial distance MG ₀ between the semiconductor crystal growth device and the initial position of the crucible POS ₀ in the semiconductor crystal growth device, the initial liquid level D ₀ of the silicon melt in the crucible, and the silicon melt and conductor _{The initial distance MG 0} between the flow cylinders is measured to obtain their initial values. This process can be obtained by direct measurement using a measuring device, such as an infrared distance measuring device.

With the growth of the silicon crystal rod in the semiconductor crystal growth device, the silicon liquid level in the crucible gradually decreases, and the height of the silicon melt liquid level continues to decrease. In order for the silicon crystal rod to grow stably, the crucible needs to be moved upwards to ensure that the crucible The stability of the silicon melt level is to ensure that the distance between the silicon melt level in the crucible and the deflector is within a certain range.

In order to control the position of the crucible moving up and down during the crystal pulling process to not exceed the safe setting range to ensure the stability of the silicon melt liquid level and the safety of the semiconductor growth device, the position of the crucible during the crystal pulling process is monitored.

Continuing to refer to FIG. 2, step S2102 is performed: obtaining the current position height POS _L of the crucible when the length of the currently grown silicon crystal rod is L and the current liquid level height D _L of the silicon melt in the crucible.

Referring to Figure 1, which shows when the crystal pulling process, the grown silicon rod length is L, the height of the current position of the crucible and the crucible 11 POS _L in this silicon melt level height D _L 11 13 In the illustrated Schematic diagram marked in. Among them, the distance between the liquid surface of the silicon melt 13 and the guide tube 16 has not changed _{relative to the initial distance MG 0.}

Exemplarily, the current position height POS _{L of the} crucible can be obtained by setting a measuring device (such as an infrared distance measuring device). Exemplary, the crucible silicon melt D _L current level height measuring means may be utilized provided (such as an infrared distance measuring device) may also be obtained using the calculated obtained.

Exemplary, using the method of calculating the current in the crucible acquiring step the liquid level height _L D silicon melt level comprises: obtaining the initial mass of the crucible silicon melt G ₀ and the length of the silicon rod is currently generated The mass G _{L at L} ; according to the initial mass G _{0 of the silicon melt in the crucible and the mass G L of} the currently generated silicon ingot, obtain the current remaining silicon melt volume V _{r of} the crucible; The current remaining silicon melt volume V _{r of} the crucible and the crucible diameter are calculated to obtain the current height D _L of the silicon melt liquid level in the crucible.

The current procedure _L D below the height of the silicon melt level is obtained using the calculation method will be described in further detail:

First, obtain the initial mass G _{0 of the silicon melt in the crucible and the mass G L} when the length of the currently generated silicon crystal rod is L. Among them, the initial quality of the silicon melt in the crucible can be obtained from the settings in the semiconductor growth device before the silicon crystal column is grown by the semiconductor growth device, and it can be obtained by direct measurement.

_{According to an example of the present invention, the mass G L} when the length of the currently generated silicon crystal rod is L is obtained by direct measurement. Exemplarily, a weighing device, such as a spring balance, is provided on the crystal pulling device. During the crystal pulling process, as the silicon crystal rod grows, the spring balance measures the mass G _L of the grown silicon crystal rod at different lengths L in real time.

。According to another example of the present invention, the obtaining of the mass G _L when the length of the currently generated silicon crystal rod is L is obtained by a calculation method:

.

為矽晶棒的橫截面積，其可以利用半導體生長裝置在晶體生長之前的設置獲得，

為矽晶體的密度。in,

Is the cross-sectional area of the silicon crystal rod, which can be obtained by the setting of the semiconductor growth device before the crystal growth,

Is the density of silicon crystals.

， 其中，

為液態矽的密度。Then, using the initial mass G _{0 of the silicon melt in the crucible and the mass G L of the} currently generated silicon ingots, _{the volume V 0 of the} current remaining silicon melt in the crucible is obtained. _{Using the initial mass G 0} of the silicon melt in the crucible _{and the mass G L of the} currently generated silicon ingot to _{obtain the mass G r} of the remaining silicon melt in the crucible, using the mass volume formula:

, in,

Is the density of liquid silicon.

_{Finally, the current height D L of the} liquid level of the silicon melt in the crucible is calculated according to _{the volume V r of the} current remaining silicon melt of the crucible and the diameter d of the crucible.

， 或者，計算D_L 為滿足

的數值解，其中，

為坩堝在深度為D時的半徑。Specifically, when the crucible is cylindrical, the following formula is used to calculate the formula:

, Or, calculate D _L to satisfy

The numerical solution of, where,

Is the radius of the crucible at depth D.

So far, it is completed to obtain the initial position height POS ₀ of the crucible, the initial liquid level D ₀ of the silicon melt in the crucible, and the initial distance MG _{0 between the silicon melt liquid level in the crucible and the deflector.} , currently grown silicon rod length L of said crucible at the current location and the POS _L exemplary description in the crucible of the liquid level _L in the method of the current D silicon melt.

It should be understood that in this embodiment, L represents an uncertain value. In this embodiment, the method of the present invention is used to provide a high degree of safety for the current position of the crucible under any growth length of the silicon crystal rod and/or the silicon melt in the crucible The liquid level position is judged.

Next, continue to refer to FIG. 2 and perform step S203: determine the current growth of silicon _{based on the initial position height POS 0} , the current position height POS _L , the initial liquid level D ₀ and the current liquid level D _L Whether the current position of the crucible is safe when the length of the crystal rod is L, where, when α ₀ POS _L -α ₁ POS ₀ <β ₀ D _0- β ₁ D _L + β ₂ MG ₀ +L _S , the current position of the crucible highly secure, when _{α 0 POS L -α 1 POS 0} > β 0 D 0 -β 1 D L + β 2 MG 0 + when L _S, the current position of the crucible highly insecure; wherein, [alpha] ₀ , α ₁ , β ₀ , β _1, and β ₂ are coefficient factors, and the L _S is a margin for setting safety control height.

It should be understood that α ₀ , α ₁ , β ₀ , β ₁ and β ₂ as coefficient factors can take any real values, which can be set by those skilled in the art according to actual application conditions. Ls, as the set safety control height margin, is also a value set by those skilled in the art according to the actual application. It is at least not lower than the height of the crucible at the beginning of the semiconductor crystal production, and at most it does not exceed the height of the crucible when the semiconductor crystal is completed. .

Exemplarily, in this embodiment, the value of α ₀ , α ₁ , β ₀ , β ₁ and β ₂ is 1. Under this value, POS _L -POS ₀ is the real-time measurement value of the crucible position change during the growth of the silicon crystal rod. And D ₀ -D _L is the calculated value of the crucible position change during the growth of the silicon crystal rod (also the change of the silicon melt level in the crucible). In the process of stable crystal pulling, the real-time measurement value of the crucible position change should be the same The calculated value of the change is not much different. In order to avoid the crucible rising too high and the risk of collision with the deflector tube, set D ₀ -D _L +MG ₀ as the maximum value of the actual measured value of the crucible position change. Since accurate calculation and measurement cannot be done in the actual manufacturing process, set a safety control height margin L _S , set when POS _L -POS ₀ ＜D ₀ -D _L +MG ₀ +L _S , the position of the crucible is safe In order to further increase the reliability of safety judgments.

In an example according to the present invention, the method for controlling the safe lifting and lowering of the silicon melt crucible further includes the steps according to the initial position height POS ₀ , the current position height POS _L, the initial liquid level height D ₀ and the current liquid level. The surface height _DL judges whether the crucible is currently in a stable range. The high or low position of the crucible will cause the liquid level in the crucible to be high or low during the process, which will cause instability, which will further impair the quality of the grown silicon ingots. For this reason, increase the judgment of the stability of the liquid level position in the crucible.

Exemplarily, it is judged whether the position of the silicon melt liquid level in the crucible is stable when the length of the currently grown silicon crystal rod is L according to the following rules: When α ₀ POS _L -α ₁ POS ₀ ＜β ₀ D ₀ -β ₁ When D _L +β ₂ MG ₀ +L _U and α ₀ POS _L -α ₁ POS ₀ > β ₀ D ₀ -β ₁ D _L + β ₂ MG ₀ -L _L , the position of the liquid level in the crucible is stable ; When α ₀ POS _L -α ₁ POS ₀ ＞β ₀ D ₀ -β ₁ D _L +β ₂ MG ₀ +L _U or α ₀ POS _L -α ₁ POS ₀ ＜β ₀ D ₀ -β ₁ D _L +β ₂ MG ₀ -L _L , the position of the liquid level in the crucible is unstable; where α ₀ , α ₁ , β ₀ , β ₁ and β ₂ are coefficient factors, and _LU and _LL are the setting liquids respectively. The upper limit of the surface and the lower limit of the set liquid level control the margin.

Similarly, α ₀ , α ₁ , β ₀ , β ₁ and β ₂ can take any real values as coefficient factors, which can be set by those skilled in the art according to actual application conditions. L _U and L _L as the upper limit of the set liquid level and the lower limit of the set liquid level control margin are also values set by those skilled in the art according to actual application conditions. They are used to control the stable growth of semiconductor crystals and the liquid level of the silicon melt can be floated. Upper limit and lower limit.

Exemplarily, in this embodiment, the value of α ₀ , α ₁ , β ₀ , β ₁ and β ₂ is 1. Under this value, the real-time measurement value POS _L -POS _{0 of the} crucible position change and the change of the silicon melt level in the crucible are controlled on the line D ₀ -D _L +MG ₀ +L _U and Control the lower line D ₀ -D _L +MG ₀ -L _L to compare separately to judge the stability of the liquid surface position in the crucible. When the crucible position changes, the real-time measured value POS _L -POS _{0 is higher than the upper control line D 0} -D _L +MG ₀ +L _U of the change of the silicon melt level in the crucible or lower than the control lower line D ₀ -D _L +MG _{When 0-} L _L , it is judged that the position of the liquid level in the crucible is unstable.

In an example according to the present invention, when it is judged that the position of the crucible is outside the safe range, the crucible is locked at the current position without moving up and down. In order to avoid the crucible colliding with the deflector, thereby avoiding safety accidents.

In an example according to the present invention, when it is judged that the position of the liquid level in the crucible is unstable, an alarm is issued. At this time, the process operator can adjust the semiconductor crystal growth device according to the alarm to avoid the growth of silicon ingots with damaged quality. Example two

In the first embodiment, a method for determining the safety of the crucible position and the stability of the silicon melt liquid level based on the measured and calculated crucible position and the position of the silicon melt liquid surface in the crucible is described. In this embodiment, a statistical method will be provided. The statistical data during the growth process of the silicon ingot in multiple tests with a safe crucible position and a stable silicon melt level are used to ensure the safety of the subsequent silicon ingot growth process. And stability.

Specifically, referring to FIG. 3, a method for controlling the safe lifting and lowering of a silicon melt crucible according to this embodiment is exemplarily described.

First, referring to FIG. 3, step S301 is performed: obtaining the current position height POS _{L of the crucible when the length of the currently grown silicon crystal rod is L.}

Exemplarily, the current position height POS _{L of the} crucible can be obtained by setting a measuring device (such as an infrared distance measuring device). In the process of semiconductor crystal growth, the position of the crucible is measured in real time, so as to monitor the position of the crucible in real time, effectively avoiding safety accidents caused by the crucible colliding with the deflector due to the deviation of the crucible position during the semiconductor crystal growth process, and also avoiding the crucible The liquid level of the medium silicon melt is unstable and the growth defect of the semiconductor crystal is noisy.

Next, continue to refer to FIG. 3 and perform step S302: Obtain the position height POS _Li of the crucible when the growth length of N silicon crystal rods is L, where i=1, 2...N.

This step can be obtained using statistical methods. In the actual operation process, real-time monitoring of the process of multiple growth of silicon ingots is carried out to obtain data on the position of the crucible during the stable growth of the silicon ingots. For example, to monitor the growth process of N silicon crystal rods, during the monitoring process, each silicon crystal rod grows L length to obtain the successive crucible position height. Exemplarily, the growth process of 100 silicon crystal rods is monitored, and the length of each silicon crystal rod is 1000 mm. In the growth process of each silicon crystal rod, starting from the initial growth, the crucible position height is obtained every 50 mm of growth. Therefore, each silicon ingot will acquire the position of the silicon ingot 20 times. Setting each silicon crystal rod to obtain the position of the crucible height every 50mm growth is based on the diameter of the crystal rod, the diameter of the crucible and the distance between the liquid surface and the deflector in actual use to ensure that each silicon crystal rod is The crucible position obtained during the growth process has sufficient density.

It should be understood that, in the foregoing embodiment, the number of silicon crystal rods is set to 100, and the crucible position height is obtained for each silicon crystal rod every 50 mm grown. Any number of silicon crystal rods and the position of the crucible obtained at any number of growth lengths are suitable for the present invention.

After counting the positions of the crucibles at different growth lengths during the growth process of the above N silicon crystal rods, according to the growth process of the silicon crystal rods currently in the process, obtain all the above N silicon crystal rods when the growth length is L. The position height of the crucible is POS _Li .

Next, continue to refer to FIG. 3 and perform step S303: obtain the position median POSM _L and the position standard deviation DEV _{L of the position POS Li} of the crucible.

The position of the crucible POS The median position of _{Li POSM L} represents the median value of the position of the crucible when the growth length of N crystal rods is L.

The position standard deviation of the position of the crucible POS _{Li DEV L} represents the degree of dispersion of the position of the crucible when the growth length of N crystal rods is L. _{Using the median and standard deviation as the comparison standard, the current position of the crucible POS L} and the position of the crucible POS _Li of the position of the _{crucible POSM L} when the growth length of the silicon ingot grown in the current silicon ingot growth process is L is the position median POSM L The difference value of is compared with the standard deviation of the position DEV _{L , and the current position height POS L} of the crucible when the growth length of the silicon ingot grown in the current silicon ingot growth process is judged is the degree of deviation of the position median POSM _{L from the position median POSM L.} Whether the crucible under the current position height is within the safe range. It realizes the use of statistical methods to judge whether the crucible at the current crucible height is within the safe range, so that the comparison result takes into account the environmental factors and component factors in the actual manufacturing process, and the accuracy of the judgment result is increased.

According to the above-described position POS of _{Li Li} crucible acquiring position POS of the crucible and the position of the median POSM _L DEV _L standard deviation, median and standard deviation using the mathematical formula for the request, it is well known to those skilled in the Technology, I won’t repeat it here.

_{According to an example of the present invention, the method for obtaining the position POS i} of the crucible when the growth length of N silicon ingots is L includes: obtaining the position height POS of the crucible for each growth of each silicon ingot in M length _{iM ; Obtain the position POS Li} of the crucible when the growth length of each silicon crystal rod is L from the plurality of position heights POS _iM of each silicon crystal rod.

According to an example of the present invention, the method for obtaining the position median POSM _L and the position standard deviation DEV _{L of the position POS i} of the crucible includes: obtaining the position median of the crucible for each growth M length according to the POSi _M Count the POSM _M and the position standard deviation DEV _M and plot them into a table or curve respectively.

_{In the above method of obtaining the position POS i} of the crucible when the growth length of N silicon crystal rods is L and the method of obtaining the position median POSM _L and the position standard deviation DEV _L of _{the position POS i of the crucible,} Use the data set obtained in the previous stage to determine whether the current position of the crucible POS _L is safe when the growth length of the silicon crystal rod is growing in the actual growth process, which makes the method of obtaining data in the judgment process simple and efficient.

_{Obtain the position median POSM L} and position standard deviation DEV _{L of} the crucible when the growth length of the crystal rod is L from the table or curve. Collect the monitoring process data of the N silicon ingots in the early stage and form a table or curve, which can be used at any time during the subsequent growth of silicon ingots, simplifying the current position of the crucible under each growth length during the subsequent growth of silicon ingots. The current position of the crucible is highly safe The process of judging the stability of the silicon melt and the liquid level in the crucible.

Next, continue to refer to FIG. 3, perform step S304: judge the current position of the crucible when the length of the currently grown silicon crystal rod is L _{according to the position height POS L} , the position median POSM _L and the position standard deviation DEV _L Is the height safe?

Exemplarily, it is determined whether the current height of the crucible is safe when the length of the currently grown silicon crystal rod is L according to the following rules: When γ ₀ POS _L -γ ₁ POSM _L <DEVL×y _S , the position of the crucible Within the safe range, when γ ₀ POS _L -γ ₁ POSM _L > DEVL×y _S , the position of the crucible is outside the safe range, γ ₀ and γ ₁ are coefficient factors, and y _S is the set safety control factor.

γ ₀ and γ ₁ are arbitrary real numbers, which can be set by those skilled in the art according to actual application conditions. y _S can be set by the process operator according to the actual process environment, crystal growth setting conditions, etc. Exemplarily, 0<y _S <10, _{and both γ 0} and γ ₁ are 1.

In an example according to the present invention, the method for controlling the safe lifting of the silicon melt crucible further includes judging the length of the currently grown silicon crystal rod _{according to the position height POS L} , the position median POSM _L and the position standard deviation DEV _L When it is L, whether the liquid level of the silicon melt in the crucible is stable.

Exemplarily, it is determined according to the following rule whether the position of the silicon melt liquid level in the crucible is stable when the length of the currently grown silicon crystal rod is L: γ ₀ POS _L -γ ₁ POSM _L <DEV _L ×y _U and When γ ₀ POS _L -γ ₁ POSM _L > DEV _L × y _L , the position of the liquid level in the crucible is stable, γ ₀ POS _L -γ ₁ POSM _L > DEV _L × y _U or γ ₀ POS _L -γ ₁ When POSM _L &lt; DEV _L ×y _L , the position of the liquid surface in the crucible is unstable.

γ ₀ and γ ₁ are coefficient factors, and y _U and y _L are the highest and lowest set liquid level factors, respectively.

Similarly, γ ₀ and γ ₁ are arbitrary real numbers, which can be set by those skilled in the art according to actual application conditions. y _U and y _L can be set by the process operator according to the actual process environment, crystal growth setting conditions, etc. Exemplarily, 0<y _U <10, 0<y _L <10, where y _{U is} less than y _S , and γ ₀ and γ ₁ are both 1.

Similarly, the position of the current POS crucible made Cheng Zhongsheng silicon rod grown silicon rod grown long length L _L of the current height position POS crucible POSM _{L Li} median difference value and the position of the DEV standard deviation _{L In comparison, the current position height POS L} of the crucible when the growth length of the silicon ingot grown in the current silicon ingot growth process is judged when the growth length is L is deviated from the position median POSM _L to determine the silicon in the crucible at the current position height Whether the position of the melt level is stable. It realizes the use of statistical methods to determine whether the position of the silicon melt in the crucible is stable at the current crucible position height, so that the comparison result takes into account the environmental factors and zero component factors in the actual manufacturing process, and the accuracy of the judgment result is increased.

It should be understood that in this embodiment, L represents an uncertain value. In this embodiment, the method of the present invention is used to provide a high degree of safety for the current position of the crucible under any growth length of the silicon crystal rod and/or the silicon melt in the crucible The liquid level position is judged.

In an example according to the present invention, when it is judged that the position of the crucible is outside the safe range, the crucible is locked at the current position without moving up and down. In order to avoid the crucible colliding with the deflector, thereby avoiding safety accidents.

In an example according to the present invention, when it is judged that the position of the liquid level in the crucible is unstable, an alarm is issued. At this time, the process operator can adjust the semiconductor crystal growth device according to the alarm to avoid the growth of silicon ingots with damaged quality. Example three

The invention also provides a device for controlling the safe lifting and lowering of the silicon melt crucible, which includes: A memory and a processor storing executable computer program instructions, and when the processor executes the executable computer program instructions, the method as described in the first embodiment or the second embodiment is executed.

A device for controlling the safe lifting and lowering of the silicon melt crucible is installed in the semiconductor crystal growth device, and the position of the crucible and the liquid level in the crucible are used to determine whether the current position of the crucible during the crystal pulling process is within a safe range, so as to avoid The crucible moves up and down beyond the limit and is damaged. At the same time, the stability of the silicon melt liquid level in the crucible is ensured during the up and down movement of the crucible, which further ensures the stable growth of the silicon crystal rod.

Exemplarily, the device for controlling the safe lifting and lowering of the silicon melt crucible further includes a locking device, and when the processor determines that the position of the crucible is outside the safe range, the locking device locks the crucible in the current position without Move up and down.

Exemplarily, the device for controlling the safe lifting and lowering of the silicon melt crucible further includes an alarm device. When the processor determines that the position of the liquid level in the crucible is unstable, the alarm device issues an alarm.

In summary, according to the method and device for controlling the safe lifting and lowering of a silicon melt crucible of the present invention, the position of the crucible and the position of the liquid level in the crucible are used to determine whether the current position of the crucible during the crystal pulling process is within a safe range, so as to avoid pulling During the crystallization process, the crucible is damaged due to the up and down movement of the crucible beyond the limit. At the same time, the stability of the liquid level of the silicon melt located in the crucible is ensured during the up and down movement of the crucible, which further ensures the stable growth of the silicon crystal rod.

The present invention has been described using the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of illustration and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above-mentioned embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications fall under the protection of the present invention. Within the range. The scope of protection of the present invention is defined by the scope of the attached invention patent application and its equivalent scope.

1: Furnace 1 10: Silicon crystal rod 11: Crucible 12: Heater 13: Silicon melt 14: Lifting device 15: Drive device 16: Diversion cylinder L: Silicon crystal rod length D _L : Current liquid level POS _L : The current position of the crucible MG ₀ : The initial distance between the liquid level of the silicon melt in the crucible and the deflector S201～S203: The process steps of the method to control the safe lifting of the silicon melt crucible S301～S304: Control the silicon melt crucible Process steps of safe lifting method

The following drawings of the present invention are used here as a part of the present invention for understanding the present invention. The drawings show the embodiments of the present invention and the description thereof to explain the principle of the present invention.

In the attached picture: Figure 1 is a schematic diagram of a semiconductor crystal growth device according to the structure; 2 is a flowchart of a method for controlling the safe lifting and lowering of a silicon melt crucible according to an embodiment of the present invention; 3 is a flowchart of a method for controlling the safe lifting and lowering of a silicon melt crucible according to an embodiment of the present invention.

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S201~S203: Process steps of the method to control the safe lifting and lowering of the silicon melt crucible

Claims (16)

A method for controlling the safe lifting and lowering of a silicon melt crucible includes: obtaining the initial position height POS ₀ of the crucible, the initial liquid level D ₀ of the silicon melt in the crucible, and the level and guide of the silicon melt in the crucible. The initial distance MG _{0 between the flow cylinders; obtain the current position height POS L} of the crucible when the length of the currently grown silicon crystal rod is L and the current liquid level height D _L of the silicon melt in the crucible; according to the The initial position height POS ₀ , the current position height POS _L , the initial liquid level D ₀ and the current liquid level D _L are judged according to the following rules to determine the current of the crucible when the length of the currently grown silicon crystal rod is L Is the position height safe: when α ₀ POS _L -α ₁ POS ₀ <β ₀ D _0- β ₁ D _L + β ₂ MG ₀ +L _S , the current position of the crucible is highly safe; when α ₀ POS _L- When α ₁ POS ₀ > β ₀ D _0- β ₁ D _L + β ₂ MG ₀ +L _S , the current position of the crucible is highly unsafe; among them, α ₀ , α ₁ , β ₀ , β ₁ and β ₂ Is the coefficient factor, and L _S is the margin for setting the safety control height. The method according to claim 1, further comprising judging the currently grown silicon _{based on the initial position height POS 0} , the current position height POS _L, the initial liquid level height D ₀ and the current liquid level D _L When the length of the crystal rod is L, whether the liquid level position of the silicon melt in the crucible is stable. According to the method described in claim 2, judge whether the liquid level position of the silicon melt in the crucible is stable when the length of the currently grown silicon crystal rod is L: when α ₀ POS _L -α ₁ POS ₀ <β ₀ When D _0- β ₁ D _L + β ₂ MG ₀ + L _U and α ₀ POS _L -α ₁ POS ₀ > β ₀ D _0- β ₁ D _L + β ₂ MG ₀ -L _L , the crucible The liquid level position of the silicon melt is stable; when α ₀ POS _L -α ₁ POS ₀ > β ₀ D _0- β ₁ D _L + β ₂ MG ₀ + L _U or α ₀ POS _L -α ₁ POS ₀ <β _{When 0} D ₀ -β ₁ D _L + β ₂ MG ₀ -L _L , the position of the liquid level of the silicon melt in the crucible is unstable; where α ₀ , α ₁ , β ₀ , β ₁ and β ₂ are coefficients The factors, L _U and L _L are the set liquid level upper limit and the set liquid level lower limit control margin respectively. The request method according to 3, wherein the step of obtaining the liquid level height _L D of the current in the crucible silicon melt level includes: obtaining a silicon melt in the crucible initial mass G ₀ and the current generated length L _{The mass G L} of the silicon ingot at time; according to the initial mass G _{0 of the silicon melt in the crucible and the mass G L of} the currently generated silicon ingot, obtain the current remaining silicon melt volume V _{r of the crucible Calculate the current height D L of the} liquid level of the silicon melt in the crucible according to the current remaining volume of the silicon melt in _{the crucible V r} and the diameter of the crucible. The method described in request item 4, wherein the obtaining the mass of the silicon ingot when the current generation length is L, G _L is calculated by the following formula: G _L = (ʃ Area _L dL ) * ρ _Si , where Area _L is the cross-sectional area _{of the silicon crystal rod, and ρ Si} is the density of the silicon crystal. The method according to claim 4, wherein said obtaining the quality G _L of the currently generated silicon ingot is obtained by directly measuring the quality of the currently generated silicon ingot. A method for controlling the safe lifting and lowering of a silicon melt crucible includes: obtaining the current position height POS _L of the crucible when the length of the currently grown silicon crystal rod is L; The position of the crucible is POS _Li , where i=1, 2. . . . . . N; Obtain the position median POSM _L and position standard deviation DEV _{L of the position POS Li} of the crucible; judge according to the following rules according to the position height POS _L , the position median POSM _L and the position standard deviation DEV _L Whether the current position of the crucible is safe when the length of the currently grown silicon crystal rod is L: γ ₀ POS _L -γ ₁ POSM _L <DEVL×y _S , the current position of the crucible is highly safe; γ ₀ POS _L -When γ ₁ POSM _L >DEVL×y _S , the current position of the crucible is unsafe; among them, γ ₀ and γ ₁ are coefficient factors, and y _S is a set safety control factor. The method according to claim 7, further comprising _{judging from the position height POS L} , the position median POSM _L and the position standard deviation DEV _{L to} determine the current growth of the silicon crystal rod when the length is L in the crucible State whether the liquid level position of the silicon melt is stable. According to the method described in claim 8, judge whether the position of the silicon melt liquid level in the crucible is stable when the length of the currently grown silicon crystal rod is L: when γ ₀ POS _L -γ ₁ POSM _L < When DEV _L × y _U and γ ₀ POS _L -γ ₁ POSM _L > DEV _L × y _L , the liquid level position of the silicon melt in the crucible is stable; when γ ₀ POS _L -γ ₁ POSM _L > DEV _{When L} × y _U or γ ₀ POS _L -γ ₁ POSM _L <DEV _L × y _L , the position of the liquid level of the silicon melt in the crucible is unstable; where γ ₀ and γ ₁ are coefficient factors, and y _U and y _L are respectively the highest factor of the set liquid level and the lowest factor of the set liquid level. The method according to claim 7, wherein the method of obtaining the position POS _Li of the crucible when the growth length of N silicon ingots is L includes: obtaining the position of the crucible when the growth length of each silicon ingot is M. Position height POS _{iM ; Obtain the position POS Li} of the crucible for each silicon ingot when the growth length is L from the plurality of position heights POS _iM of each silicon ingot. The method according to claim 10, wherein the method of obtaining the position median POSM _L and the position standard deviation DEV _{L of the position POS i} of the crucible includes: obtaining the length of each growth M according to the POS _iM The position median POSM _M and position standard deviation DEV _{L of the crucible are plotted as a table or curve respectively; the position median POSM L} and position of the crucible when the growth length of the ingot is L is obtained from the table or curve Standard deviation DEV _L. According to the method described in claim 1 or 7, when it is determined that the position of the crucible is outside the safe range, the crucible is locked at the current position without moving up and down. According to the method described in claim 3 or 9, when it is judged that the position of the liquid level in the crucible is unstable, an alarm is issued. A device for controlling the safe lifting and lowering of a silicon melt crucible includes: a memory and a processor storing executable computer program instructions, and the processor executes items such as request items 1, 2 when executing the executable computer program instructions. , 3, 7, 8, or 9. The device according to claim 14, further comprising a locking device, when the processor determines that the position of the crucible is outside the safe range, the locking device locks the crucible at the current position without moving up and down. The device according to claim 14, further comprising an alarm device, when the processor determines that the position of the liquid level in the crucible is unstable, the alarm device issues an alarm.

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